(Delphi DLL) ABN AMRO Create Signed JSON Web Token

Demonstrates how to create a signed JWT to be used for authenticating requests to the ABN AMRO REST API's.

For more information, see https://developer.abnamro.com/get-started#headingFive

Chilkat for Delphi Downloads Chilkat non-ActiveX DLL for Delphi Chilkat ActiveX DLL for Delphi * The examples here use the non-ActiveX DLL.

uses
    Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
    Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, Jwt, PrivateKey, Rsa, PublicKey, JsonObject;

...

procedure TForm1.Button1Click(Sender: TObject);
var
rsa: HCkRsa;
success: Boolean;
privkey: HCkPrivateKey;
pubkey: HCkPublicKey;
jwt: HCkJwt;
jsonHeader: HCkJsonObject;
jsonPayload: HCkJsonObject;
curDateTime: Integer;
jwtStr: PWideChar;

begin
// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

// Create public/private key pair (RSA)
rsa := CkRsa_Create();

// Generate a 2048-bit key.
success := CkRsa_GenerateKey(rsa,2048);
if (success <> True) then
  begin
    Memo1.Lines.Add(CkRsa__lastErrorText(rsa));
    Exit;
  end;

// Export the key to PEM files.
// Write one PEM file for the private key, and one for the public key.
privkey := CkRsa_ExportPrivateKeyObj(rsa);
success := CkPrivateKey_SavePemFile(privkey,'qa_data/pem/abnAmroPrivateKey.pem');

pubkey := CkRsa_ExportPublicKeyObj(rsa);
success := CkPublicKey_SavePemFile(pubkey,True,'qa_data/pem/abnAmroPublicKey.pem');
// Note: Please share your public key along with your app name and developer email id at api.support@nl.abnamro.com. 
// Token generation will not work unless public key is associated with your app.

// Create the JWT.
jwt := CkJwt_Create();

// Create the header:
// {
//     "typ": "JWT",
//     "alg": "RS256"
// }
jsonHeader := CkJsonObject_Create();
CkJsonObject_UpdateString(jsonHeader,'typ','JWT');
CkJsonObject_UpdateString(jsonHeader,'alg','RS256');

// Create the payload:
// {
//     "nbf": 1499947668,
//     "exp": 1499948668,
//     "iss": "me",
//     "sub": "anApiKey",
//     "aud": "https://auth-sandbox.abnamro.com/oauth/token"
// }
jsonPayload := CkJsonObject_Create();

curDateTime := CkJwt_GenNumericDate(jwt,0);

// Set the "not process before" timestamp to now.
success := CkJsonObject_AddIntAt(jsonPayload,-1,'nbf',curDateTime);

// Set the timestamp defining an expiration time (end time) for the token
// to be now + 1 hour (3600 seconds)
success := CkJsonObject_AddIntAt(jsonPayload,-1,'exp',curDateTime + 3600);

CkJsonObject_UpdateString(jsonPayload,'iss','me');
CkJsonObject_UpdateString(jsonPayload,'sub','anApiKey');
CkJsonObject_UpdateString(jsonPayload,'aud','https://auth-sandbox.abnamro.com/oauth/token');

// Produce the smallest possible JWT:
CkJwt_putAutoCompact(jwt,True);

jwtStr := CkJwt__createJwtPk(jwt,CkJsonObject__emit(jsonHeader),CkJsonObject__emit(jsonPayload),privkey);
if (CkJwt_getLastMethodSuccess(jwt) <> True) then
  begin
    Memo1.Lines.Add(CkJwt__lastErrorText(jwt));
    Exit;
  end;

CkPrivateKey_Dispose(privkey);
CkPublicKey_Dispose(pubkey);

// Here is the JWT:
Memo1.Lines.Add(jwtStr);

CkRsa_Dispose(rsa);
CkJwt_Dispose(jwt);
CkJsonObject_Dispose(jsonHeader);
CkJsonObject_Dispose(jsonPayload);

end;